There frequently arises a need for the movement of relatively heavy vehicles, such as house trailers, boat trailers, and aircraft from one position to another, for example, in positioning a trailer. It is often difficult, if not impossible, for an individual to move such a vehicle unassisted. Additionally, it is difficult to control the direction of movement. As a result of this need, a number of devices have been provided, that may be utilized with such vehicles to enable the manual positioning and movement of the vehicles with reduced effort and improved control.
Some of these devices incorporate a ground engaging belt or chain, or utilize elaborate gear driving mechanisms, all of which are likely to become fouled with dirt and other foreign matter. Additionally, many of those devices do not protect against roll back or provide for adequate steerage control.
Prior art devices incorporating drive mechanisms, while affording adequate mechanical advantage to move the vehicle, are excessively bulky and of complex and expensive construction.
It is therefore desirable to have an apparatus for moving and positioning vehicles that enables a single operator to move a heavy vehicle, and at the same time maintain precise directional control, especially if such an apparatus also provides for holding the vehicle against roll back on a grade and for emergency and parking brake capability.